This may be somewhat off topic (my apologies), but here goes...

We have a 1950's style brick ranch house that has parging on the
foundation as well as the lower levels of brick, below ground level.
We are planning on building a dry stack wall in the front of the house
to make level flower beds. Once we backfill the beds there will be
about 10-15" of un-parged brick that will be below the "new" ground
level, especially at the ends of the house (our property slopes away
from the house on either side). I'm
going on the assumption I should parge the brick to keep it sealed,
right? But what do I use? Just some pre-mixed cement, or is there a
special product or "formula" I should use? Also, is there any
particular prep I need to promote adhesion? What about cure time?

Any other suggestions, tips, words of advice on the parging/skim coat
as well as the dry-stack wall would be most appreciated.

Thanks.

-Dave